Kinetics of dislocation cross-slip: A molecular dynamics study

被引：23
作者：
Oren, E. [1 ]
Yahel, E. [2 ]
Makov, G. [1 ]
机构：
[1] Ben Gurion Univ Negev, Dept Mat Engn, IL-8410501 Beer Sheva, Israel
[2] NRCN, Phys Dept, POB 9001, IL-84190 Beer Sheva, Israel
来源：
COMPUTATIONAL MATERIALS SCIENCE | 2017年 / 138卷
关键词：
Dislocations; Kinetics; Molecular dynamics simulations; Thermally activated processes; Cross-slip; CENTERED-CUBIC NICKEL; ATOMISTIC SIMULATIONS; SCREW DISLOCATIONS; FCC METALS; NUCLEATION; INTERSECTIONS; ANNIHILATION; DEPENDENCE; MECHANISMS; COPPER;
D O I：
10.1016/j.commatsci.2017.06.039
中图分类号：
T [工业技术];
学科分类号：
08 ;
摘要：
The kinetics of cross-slip and annihilation of a screw dislocation dipole in face-centered cubic (FCC) copper crystals were studied by multiple molecular-dynamics simulations of long (200b) dislocations at selected stresses and temperatures with the aim to account for the thermally activated nature of the cross-slip process. A novel cross-slip mechanism was identified; this mechanism required the formation of a finite length constriction before cross-slip could be initiated. It was shown that point constrictions are not the transition state of cross-slip. A study of the kinetics confirmed that cross-slip is a first-order process. By fitting the rate constant to an Arrhenius form, the activation energy was found to be 1:05 eV +/- 15%. The activation volume for the Escaig stress in the glide plane was in the range of 5-40b(3), and the prefactor for the rate constant was evaluated to be 1 THz/b. (C) 2017 Elsevier B.V. All rights reserved.
引用
收藏
页码：246 / 254
页数：9
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